Fluctuations in Subjective Defecation and Objective Stool Shapes During the Menstrual Cycle

Abstract

The purpose of this study was to clarify the fluctuations in subjective defecation and objective stool shapes during the menstrual cycle. Seventeen healthy female volunteers (20- 30 years old) were used. The investigation period was 28 days. The questionnaire consisted of matters regarding menstruation, subjective defecation, and lifestyle. The objective stool shape was scored according to The Bristol Stool Scale. In the questionnaire on defecation, 88% of the subjects experienced subjective changes in defecation. Large changes in the shapes of the stools were observed both before and during menstruation. Approximately 60% of subjects experienced constipation one week before menstruation, while 60% of subjects experienced diarrhea during menstruation. The scores using the Bristol Stool Scale were 3.8±1.0 at one week before menstruation and 4.3±1.0 during menstruation. Although no major changes were observed, variations in objective defecation were observed in 53% of the subjects. Seventy-one percent of the subjects reported subjective defecation that was consistent with the objective stool shape results during their menstrual cycles. Twenty-nine percent of subjects had subjective fluctuations only, and 70% of subjects had fluctuations in stool frequency. Thus, the present study clarified the occurrence of fluctuations in subjective defecation and objective stool shape during the menstrual cycle.